Biological engineering or bioengineering (including biological systems engineering) is the application of concepts and methods of biology (and secondarily of physics, chemistry, mathematics, and computer science) to solve real-world problems related to the life sciences or the application thereof, using engineering's own analytical and synthetic methodologies and also its traditional sensitivity to the cost and practicality of the solution(s) arrived at. In this context, while traditional engineering applies physical and mathematical sciences to analyze, design and manufacture inanimate tools, structures and processes, biological engineering uses primarily the rapidly developing body of knowledge known as molecular biology to study and advance applications of living organisms.
An especially important application is the analysis and cost-effective solution of problems related to human health, but the field is much more general than that. For example, biomimetics is a branch of biological engineering which strives to find ways in which the structures and functions of living organisms can be used as models for the design and engineering of materials and machines. Systems biology, on the other hand, seeks to utilize the engineer's familiarity with complex artificial systems, and perhaps the concepts used in "reverse engineering", to facilitate the difficult process of recognition of the structure, function, and precise method of operation of complex biological systems.
The differentiation between biological engineering and biomedical engineering can be unclear, as many universities loosely use the terms "bioengineering" and "biomedical engineering" interchangeably. Biomedical engineers are specifically focused on applying biological and other sciences toward medical innovations, whereas biological engineers are focused principally on applying engineering principles to biology - but not necessarily for medical uses. Hence neither "biological" engineering nor "biomedical" engineering is wholly contained within the other, as there can be "non-biological" products for medical needs as well as "biological" products for non-medical needs (the latter including notably biosystems engineering).
Biological engineering is a science-based discipline founded upon the biological sciences in the same way that chemical engineering, electrical engineering, and mechanical engineering can be based upon chemistry, electricity and magnetism, and classical mechanics, respectively.
Biological engineering can be differentiated from its roots of pure biology or other engineering fields. Biological studies often follow a reductionist approach in viewing a system on its smallest possible scale which naturally leads toward tools such as functional genomics. Engineering approaches, using classical design perspectives, are constructionist, building new devices, approaches, and technologies from component concepts. Biological engineering utilizes both kinds of methods in concert, relying on reductionist approaches to identify, understand, and organize the fundamental units which are then integrated to generate something new. In addition, because it is an engineering discipline, biological engineering is fundamentally concerned with not just the basic science, but its practical application of the scientific knowledge is to solve real-world problems in a cost-effective way.
Although engineered biological systems have been used to manipulate information, construct materials, process chemicals, produce energy, provide food, and help maintain or enhance human health and our environment, our ability to quickly and reliably engineer biological systems that behave as expected is at present less well developed than our mastery over mechanical and electrical systems.
ABET, the U.S.-based accreditation board for engineering B.S. programs, makes a distinction between biomedical engineering and biological engineering, though there is much overlap (see above). Foundational courses are often the same and include thermodynamics, fluid and mechanical dynamics, kinetics, electronics, and materials properties. According to Professor Doug Lauffenberger of MIT, biological engineering (like biotechnology) has a broader base which applies engineering principles to an enormous range of size and complexities of systems ranging from the molecular level - molecular biology, biochemistry, microbiology, pharmacology, protein chemistry, cytology, immunology, neurobiology and neuroscience (often but not always using biological substances) - to cellular and tissue-based methods (including devices and sensors), whole macroscopic organisms (plants, animals), and up increasing length scales to whole ecosystems.
The word bioengineering was coined by British scientist and broadcaster Heinz Wolff in 1954. The term bioengineering is also used to describe the use of vegetation in civil engineering construction. The term bioengineering may also be applied to environmental modifications such as surface soil protection, slope stabilisation, watercourse and shoreline protection, windbreaks, vegetation barriers including noise barriers and visual screens, and the ecological enhancement of an area. The first biological engineering program was created at Mississippi State University in 1967, making it the first biological engineering curriculum in the United States. More recent programs have been launched at MIT  and Utah State University.
Biological engineers or bioengineers are engineers who use the principles of biology and the tools of engineering to create usable, tangible, economically viable products. Biological engineering employs knowledge and expertise from a number of pure and applied sciences, such as mass and heat transfer, kinetics, biocatalysts, biomechanics, bioinformatics, separation and purification processes, bioreactor design, surface science, fluid mechanics, thermodynamics, and polymer science. It is used in the design of medical devices, diagnostic equipment, biocompatible materials, renewable bioenergy, ecological engineering, agricultural engineering, and other areas that improve the living standards of societies.
In general, biological engineers attempt to either mimic biological systems to create products or modify and control biological systems so that they can replace, augment, or sustain chemical and mechanical processes. Bioengineers can apply their expertise to other applications of engineering and biotechnology, including genetic modification of plants and microorganisms, bioprocess engineering, and biocatalysis.
Because other engineering disciplines also address living organisms (e.g., prosthetics in bio-mechanical engineering), the term biological engineering can be applied more broadly to include agricultural engineering and biotechnology, which notably can address non-healthcare objectives as well (unlike biomedical engineering). In fact, many old agricultural engineering departments in universities over the world have rebranded themselves as agricultural and biological engineering or agricultural and biosystems engineering. Biological engineering is also called bioengineering by some colleges and biomedical engineering is called bioengineering by others, and is a rapidly developing field with fluid categorization. Depending on the institution and particular definitional boundaries employed, some major fields of bioengineering may be categorised as (note these may overlap):
- Biological systems engineering
- Biomedical engineering: biomedical technology, biomedical diagnostics, biomedical therapy, biomechanics, biomaterials.
- Genetic engineering (involving both of the above, although in different applications): synthetic biology, horizontal gene transfer.
- Bioprocess engineering: bioprocess design, biocatalysis, bioseparation, bioinformatics, bioenergy
- Cellular engineering: cell engineering, tissue engineering, metabolic engineering.
- Biomimetics: The use of knowledge gained from reverse engineering evolved living systems to solve difficult design problems in artificial systems.
- NIH working definition of bioengineering http://www.becon.nih.gov/bioengineering_definition.htm accessed, 1/1/2007
- Cuello JC, Engineering to biology and biology to engineering, The bi-directional connection between engineering and biology in biological engineering design, Int J Engng Ed 2005, 21, 1-7
- Riley MR, Introducing Journal of Biological Engineering, Journal of Biological Engineering 1,1, 2007, http://www.jbioleng.org,
- Endy D, Foundations for engineering biology. Nature 438,449-4 2005, http://www.nature.com/nature/journal/v438/n7067/full/nature04342.html
- ABET http://www.abet.org/Linked%20Documents-UPDATE/Criteria%20and%20PP/A004%2010-11%20Accredition%20Policy%20and%20Procedure%20Manual%2011-05-09.pdf, accessed 9/8/2010.
- Linsenmeier RA, Defining the Undergraduate Biomedical Engineering Curriculum http://www.vanth.org/curriculum/def_bme_curr.pdf
- Johnson AT, Phillips WM: "Philosophical foundations of biological engineering". Journal of Engineering Education. 1995, 84:311-318
- http://web.mit.edu/be/index.shtml, 4/14/2011
- http://web.mit.edu/be/people/lauffenburger.shtml, 4/14/2011
- "Professor Heinz Wolff". Heinzwolff.co.uk. Retrieved 2011-11-13.
- "Agricultural & Biological Engineering: History of the Department". Abe.msstate.edu. Retrieved 2011-11-13.
- "MIT | Department of Biological Engineering". Web.mit.edu. Retrieved 2011-11-13.
- "Biological Engineering". be.usu.edu. Retrieved 2011-11-13.
- Bioengineering Society
- Department of Bioengineering, Imperial College London
- Biomedical Engineering Society
- Institute of Biological Engineering
- Benjoe Institute of Systems Biological Engineering
- American Institute of Medical and Biological Engineering
- American Society of Agricultural and Biological Engineers
- Society for Biological Engineering part of AIChE
- Journal of Biological Engineering, JBE
- Biological Engineering Transactions